2 Samuel 18:1-8 NIV
David mustered the men who were with him and appointed over them commanders of thousands and commanders of hundreds. David sent out his troops, a third under the command of Joab, a third under Joab’s brother Abishai son of Zeruiah, and a third under Ittai the Gittite. The king told the troops, “I myself will surely march out with you.”
But the men said, “You must not go out; if we are forced to flee, they won’t care about us. Even if half of us die, they won’t care; but you are worth ten thousand of us. It would be better now for you to give us support from the city.”
The king answered, “I will do whatever seems best to you.”
So the king stood beside the gate while all his men marched out in units of hundreds and of thousands. The king commanded Joab, Abishai and Ittai, “Be gentle with the young man Absalom for my sake.” And all the troops heard the king giving orders concerning Absalom to each of the commanders.
David’s army marched out of the city to fight Israel, and the battle took place in the forest of Ephraim. There Israel’s troops were routed by David’s men, and the casualties that day were great—twenty thousand men. The battle spread out over the whole countryside, and the forest swallowed up more men that day than the sword.
NIV: New International Version